Enhanced Welding Operator Quality Performance Measurement: Work Experience-Integrated Bayesian Prior Determination

Measurement of operator quality performance has been challenging in the construction fabrication industry. Among various causes, the learning effect is a significant factor, which needs to be incorporated in achieving a reliable operator quality performance analysis. This research aims to enhance a previously developed operator quality performance measurement approach by incorporating the learning effect (i.e., work experience). To achieve this goal, the Plateau learning model is selected to quantitatively represent the relationship between quality performance and work experience through a beta-binomial regression approach. Based on this relationship, an informative prior determination approach, which incorporates operator work experience information, is developed to enhance the previous Bayesian-based operator quality performance measurement. Academically, this research provides a systematic approach to derive Bayesian informative priors through integrating multi-source information. Practically, the proposed approach reliably measures operator quality performance in fabrication quality control processes.Comment: 8 pages, 5 figures, 2 tables, i3CE 201

Enhanced Welding Operator Quality Performance Measurement: Work Experience-Integrated Bayesian Prior Determination

Measurement of operator quality performance has been challenging in the construction fabrication industry. Among various causes, the learning effect is a significant factor, which needs to be incorporated in achieving a reliable operator quality performance analysis. This research aims to enhance a previously developed operator quality performance measurement approach by incorporating the learning effect (i.e., work experience). To achieve this goal, the Plateau learning model is selected to quantitatively represent the relationship between quality performance and work experience through a beta-binomial regression approach. Based on this relationship, an informative prior determination approach, which incorporates operator work experience information, is developed to enhance the previous Bayesian-based operator quality performance measurement. Academically, this research provides a systematic approach to derive Bayesian informative priors through integrating multi-source information. Practically, the proposed approach reliably measures operator quality performance in fabrication quality control processes.Comment: 8 pages, 5 figures, 2 tables, i3CE 201

Domain-specific risk assessment using integrated simulation: A case study of an onshore wind project

Although many quantitative risk assessment models have been proposed in literature, their use in construction practice remain limited due to a lack of domain-specific models, tools, and application examples. This is especially true in wind farm construction, where the state-of-the-art integrated Monte Carlo simulation and critical path method (MCS-CPM) risk assessment approach has yet to be demonstrated. The present case study is the first reported application of the MCS-CPM method for risk assessment in wind farm construction and is the first case study to consider correlations between cost and schedule impacts of risk factors using copulas. MCS-CPM provided reasonable risk assessment results for a wind farm project, and its use in practice is recommended. Aimed at facilitating the practical application of quantitative risk assessment methods, this case study provides a much-needed analytical generalization of MCS-CPM, offering application examples, discussion of expected results, and recommendations to wind farm construction practitioners

Determining a reasonable concession period for private sector provision of public works and service

The concession period is one of the most important issues to be addressed in private sector provision of public works and services through concession arrangements as it, to some extent, demarcates the rights and responsibilities between public and private sectors in a project's life cycle, and it is also critical to the project's sustainable development. This paper proposes a methodology for the determination of an appropriate length of the concession based on a win-win principle for parties involved and exercises simulation techniques in measuring and evaluating construction and economic uncertainties and risks. A case study of a hypothetical infrastructure project is provided to demonstrate the application of the proposed methodology, mathematical model, and simulation techniques

Enhancing Value Engineering Process by Incorporating Inventive Problem-Solving Techniques

The creativity phase is critical to the success of a value engineering exercise, in which the brainstorming technique is deployed to generate ideas. One shortcoming of the brainstorming technique is its lack of direction in problem solving, and consequently the efficiency is low in generating innovative and useful ideas. To overcome this shortcoming, this paper has explored the possibility of incorporating the theory of inventive problem solving (TRIZ) into the workshop session of the value engineering exercise by initiating three new procedures in this session: (1) an initial design procedure to examine the functions of a proposed project; (2) a function trimming procedure to fully utilize existing resources and ensure low life-cycle cost and sustainability of the proposed project; and (3) an interaction analysis procedure to assess the proposed project in a broad perspective with social, economic, and environmental awareness. A case study has indicated the workability of the modified workshop procedures and the usefulness of TRIZ tools and techniques in efficiently and effectively creating innovative ideas

Integration of predetermined motion time systems into simulation modeling of manual construction operations

Simulation modeling is a powerful tool widely used for designing construction processes and improving the efficiency of operations. However, there is often difficulty in estimating the duration of manual tasks for simulation purposes due to its dependence on the physical attributes of the worker performing the task. When designing a new process, there is usually a lack of sufficient data regarding the required duration for manual tasks, and in the case of evaluating and improving existing processes, there is no benchmark data for workers’ performance to enable comparison of the efficiency of the existing process. This study attempts to address this issue by exploring micro-motion-level simulation modeling in order to provide standard motion time required to perform a manual task for effective workplace design. The research method involves integrating a Predetermined Motion Time System (PMTS) into discrete event simulation, which provides the production planner with a standard task duration within which a worker must complete the task without delays or idling. As a case study, a manual task taking place in the production line of a construction steel fabrication company has been modeled using the developed automation tool in order to verify the feasibility of the proposed approach. The results show high correlation between the simulation model output and the actual time data from the jobsite and confirm the validity of the approach and its effectiveness in evaluating the productivity of the existing operations and providing detailed information for process improvement.Non UBCUnreviewedFacultyOthe

Time of Sampling Strategies for Asphalt Pavement Quality Assurance

The cost of quality assurance programs in asphalt road construction is high in part because of the need for daily testing. This paper demonstrates the methodology used to investigate the timing of sampling and its effect on the quality assurance program. Fourteen lots over two highway paving projects were tested twice: during construction on a daily basis, and after construction was complete. Three quality measures were compared, namely asphalt content, degree of compaction, and aggregate gradation. The test data during construction were obtained from two sources: the consultant’s quality assurance, and the contractor’s quality control. One-way ANOVA tests and T-tests were used to compare the means. In addition, the arithmetic difference between the means was reviewed to understand how the time of sampling might affect contractor payment adjustments

Distributed agent-based simulation of construction projects with HLA

Simulation techniques can provide a resource-driven schedule and answer many hypothetical scenarios before project execution to improve on conventional project management software applications for large-scale con-struction projects. However, the current process of simu-lation and optimization of resource utilization is a time consuming process especially for large-scale projects. This study employs High Level Architecture (HLA) to develop distributed agent based simulation models. These models are composed of several individual modeling components (federates) that can cooperate with each other for the simulation model (interoperability). These feder-ates are developed in a generic way for reuse on future construction projects. A number of agent-based federates are considered for managing various aspects of the project and to enhance the performance of the simulation model. This framework is illustrated using two case studies, module assembly yard and tower crane, that investigate the feasibility of the proposed approach.

Tunnel boring machine positioning automation in tunnel construction

Purpose Tunnel construction using a tunnel boring machine (TBM) entails precise machine positioning and guidance in the underground space. In contrast to traditional laser-based machine guidance solutions, the proposed research aims to develop an automation alternative to facilitate TBMguidance and as-built tunnel alignment survey during tunnelling operations. Method A fully automated system is proposed, in which a robotic total station is employed to automate the continuous process of TBM -tracking and positioning in the 3D underground working space. ZigBeebased wireless sensor networks are applied for wireless data communication inside the tunnel. A camera is mounted on the telescope of the total station to capture online operational videos. Real-time survey data are thus acquired, processed and displayed on a tablet PC on the fly, resulting in: (i) TBM's precise coordinates in the underground space; (ii) three-axis body rotations of the TBM; (iii) tunnelling chainage progress; and (iv) line and grade deviations of the tunnel alignment. Results & Discussion For proof-of-concept, a prototype TBM-positioning automation system has been developed in-house for laboratory testing. The accuracy testing was conducted by the automation system and a specialist surveyor independently. The differences between the two sets of surveying results were less than 2mm, which sufficiently validated the high accuracy of the automation solution. In April 2012, the prototype will be field tested on a 2.4 m diameter and 1,040 m long drainage tunnel project in Edmonton, Canada